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W M. DIGKERSON.

BAND SAW MILL. No. 340,990. Patented May 4, 1886.

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UNITED STATES PATENT OFFICE.

WILLIAM M. DICKERSON, OF INDIANAPOLIS, INDIANA, ASSIGNOR OF ONE- HALF TOLEVIS V. HOLLOWAY, OF SAME PLACE.

BAN D-SAVV M|LL.-

SPECIFICATION forming part of Letters Patent No. 34:0,990, dated May 4,1886.

Application filed February 8, 1886. Serial No. 191,253; (No model.)

To all whom it may concern:

Be it known that I, WILLIAM M. DIOKER- SON, a resident of Indianapolis,Marion county, Indiana, have made certain new and useful Improvements inBand-Saw Mills, a description of which is set forth in the followingspecification, reference being made to the accompanying drawings, in theseveral figures of which like letters represent like parts.

My invention relates to an improvement in the mechanism for hanging andadjusting the mechanism which carries the band saw and regulates itstension upon the pulleys, and will be understood from the followingdescription.

In the drawings, Figure I is a side view of of my device, partly insection; and Fig. II is a similar view, on a larger scale, of the lowerparts thereof.

In detail, P is a hollow metal pillar, firmly bolted to a base, B.

s is a sliding plate or bar, which is allowed to move against one of thefaces of the pillar P, and at the upper end of this slide 8 the yokev,which carries the upper pulley, p, is pivoted at the point 1. This yoke3 thus pivoted or hinged to the upper end of the slide 3, providesbearings for the axle a of the upper pulley, p, and a lever, Z, isconnected to one of the sides of this yoke, passing through an openingof corresponding size in the pillar P. w is a counterbalance, which isadjustable upon the end of this lever Z, so as to equalize the weightcaused by the overhang of the yoke y and its load. On the lower end ofthis yoke is a small arm or projection, 19*, and con nected with thisarm is a ratchet, r, and pawl terminating in a screw, sc,which ispivoted at 2 to the outer end of a second lever, Z, also passing throughthe pillar P, and having its fulcrum on a pivot, 3. The outer end ofthis lever Z terminates in a right angle, and also carries acounter-balance or weight, w, the object of this weight being to assistin balancing the weight of the yoke, with its mechanism, when the saw isstretched. The screw so terminates in a socket formed in the base b,which is connected with the screw, this base only resting upon the uppersurface of the arm of the bracket b, which is slightly inclined, so thatthe movement of the screw so simply moves the li'ase up and down thisincline, the base I) being in no wise connected to the bracket 1).

p is the lower saw-pulley, mounted upon an axle, a, having hearings onone side in the bracketarm b, and on the other side in a projectionconnected with the base of the framework.

f is a frame-work bolted to the face of the slide 8. This frame-work hastwo projecting lugs on its upper side, which are threaded to admit theadjusting-screws s, between which the arm 12 passes, and below andwithin the body of the frame-work f are coil-springs sp on either sideof the arm p, and the ends of the frame are threaded to receive thetensionscrews 3, which on their inner ends have followers bearingagainst the ends of the coilspriugs.

The slide sis provided with the frictionscrews 6 and 7, for bearingagainst the face of the pillar P and preventing the slide from fallingdownward while balancing the yoke.

The operation of my device is as follows: The yoke y is drawn out orpushed in so as to bring the upper pulley, p, as near as possible inline with the lower pulley, and the screws .9 s are then adjusted sothat their ends will be equidistant from each side of the arm p, and nottouching this arm. The frictionscrews 6 and 7 during this operation aresup posed to have been tightened against the face of the pillar P, theratchet r and the screw connected therewith being loose. The saw is thenput on over the pulleys, and by means of the ratchet 1' and the screw 80the arm 19 is forced up, carrying the yoke y and the pulley p,stretching the saw as much as desired upon its upper and lower pulleys.WVhen this is done, the oounterpoises on the upper and lower levers, ZZ, are fastened by set-screws to the desired point on these levers, andthe springs 81), by means of the screws on either side, are carefullyadjusted so that the bearing on either side of the arm 1 is the same,the upper screws, 8, being left free from contact with the sides of thearm 19 so that in case of any uneven or unequal pressure upon eitheredge of the saw, there will be provided an elastic bearing by means ofthe springs on either side of the arm 12, which is connect- IOC ed withthe yoke which carries the upper pulley, the elasticity of the springswill resist such uneven pressure on the one side, and the elasticity ofthe spring on the other side will in some measure equalize it, so that arigid hearing or pressure 011 the arm 19 is avoided by means of thesecompensating elastic springs, and I thus provide a counterpoiseconnected with the yoke 3/ on one side, and a counterpoise connectedwith the screw so at the bottom, steadying the movement of the yokemechanism at all times while the saw is in motion, and also providing anelastic bearing by means of the springs and adjusting mechanism, and bymeans of the screws 8, which will allow a nicety of adjustment, keepingthe sawpulleys substantially in line with each other; and in case oneside of the saw becomes more heated than the other side there is readymeans provided in the adjusting mechanism herein indicated for easing upthe strain on that side of the saw.

I am aware that band saw pulleys carried in a yoke pivoted to a hollowpillar are not new, and do not broadly claim the same as my invention.

What I do claim as my invention, and desire to secure by Letters Patent,is the following:

1. A bandsaw mill wherein the upper pulley is carried in a yoke pivotedto a slide, connected with one face of a hollow pillar, I, the overhangof the yoke and its pulley counterbalanced by means of a primary leverconnected to the inside end of said yoke, extending outward past thesupporting-pillar, and provided with an adjustable weight on such outerend, and further counterbalanced by a secondarylever connected with ascrew mechanism operating upon the yoke-supporting bar for bringing thepulleys in line, this secondary lever extending outward and providedalso with an adjustable counter-weight, sub stantially as and for thepurposes described.

2. A band-saw mill wherein the upper sawpulley is carried in a yokepivoted or hinged to the upper part of the supporting-pillar, providedwith a counter-balance on the lower side of said yoke, and also providedwith an arm which is connected with a ratchet for raising and loweringthe yoke and the pulley it carries, such connecting-arm passing througha frame-work provided with one or more pressuresprings, furnishing anelastic bearing against the sides of such projecting arm for keeping theupper and lower pulleys in line with each other, substantially asdescribed.

3. A. band-saw mill whose upper pulley is carried by a yoke hinged tothe upper portion of a supporting-pillar and provided with a lateralcounter-balance on one side, a ratchet mechanism below such yoke, andconnected with it so as to elevate the yoke and its pulley for givingtension to the saw when slipped on over the upper and lower pulleys, asecond lever pivoted to the screw of such ratchet,

having a suitable counter-balance on its outer end, and adjustingmechanism connected with a frame-work bolted to the side of thesupporting-pillar and provided with one or more coil-springs forfurnishing an elastic bearing to the sides of a projection from theupper part of the yoke, and a lower saw-pulley and bandsaw, all combinedsubstantially as described.

4:. The adjusting mechanism herein described, composed of a suitableframe-work, f, bolted to the slide 8, and provided with pressure-springssp, contained in such frame, tension-screws s,operating upon suchsprings,

adjusting-screws s, between which the pro-' jection from the yokepasses, and a suitable screw-and-ratchet mechanism connected therewith,the upper pulley-whcel, p, mounted in the yoke 31, which is pivoted tothe pillar P, the lower pulley-wheehp', having hearings in the lowerbracket and base, the lifting mech anism composed of the screw so andits ratchet, its lower end resting in the base Z),adapted to slide onthe inclined upper surface of the bracket Z), the yoke-bar 10, connectedwith the yoke y, the lever Z, and its counter-balance w, all combinedsubstantially as described.

5. A band-saw mill whose upper pulley is carried in a yoke hinged to theupper end ofa supporting'pillar, such yoke and pulley balanced by asuitable counterpoise connected therewith, and one or more coil springsoperating against either side of a projection below the yoke,incombination with adj Listing-screws above such springs, the upper andlower sawpulleys mountedinsuitable'bearings, as herein described, thelifting-screw sc,with its ratchet resting upon the lower bracket, I),and operating against asupportingbar on the under side of the yoke a,all combined substantially as described.

6. In a band-saw mill, the yoke hinged to the slide s at one end andadapted to move upon the face of the pillar P, the upper sawpulley,10,mounted upon an axle having bearings in the sides of such yoke, thelateral balancinglever Z, with its weight w, the yokesupporting bar 12connected with the ratchet mechanism, and a screw below pivoted at 2 tothe secondary lever Z, provided with a counter-balance, w, the lowerpulley, 10, mounted upon the axle a, having hearings in the bracket-armb and a projection from the frame, and the adjusting mechanism composedof the frame f, the springs 8p, the tension-screws s, the framef, boltedto the slide 8, and the adjusting-screws s, all combined substantiallyas described.

In witness whereof I have hereunto set my hand this 1st day of February,1886.

WILLIAM M. DIGKERSON.

Witnesses:

O. P. J AOOBS, HATTIE MURRY.

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